Pre-heat your oven to 350.
In a mixing bowl, combine the ground turkey with ½ teaspoon salt, ¼ teaspoon black pepper and the sage, thyme, marjoram and crushed red pepper. Stir (or mush with your hands or a fork) until the turkey is well combined with the seasonings.
Mist an 8”-10” oven-safe nonstick walled skillet with cooking spray and bring to medium heat. Add the seasoned turkey and cook, breaking up with a wooden spoon, until the turkey is cooked through and broken into bite-sized pieces. Add the chopped apples and cook for 2-3 more minutes, stirring a few times.
While the turkey is cooking, break the eggs into a large mixing bowl and whisk together until just combined. Add the yogurt, the remaining ¼ teaspoon of salt, ¼ teaspoon of pepper and shredded cheddar and stir together until mixed.
When the turkey and apples are cooked, transfer them into the bowl containing the egg mixture and stir together. Spray the skillet you used liberally with cooking spray and then pour the egg mixture into the skillet. Cook on a burner set to medium heat for 5-7 minutes until the very outside edge of the frittata starts to turn opaque/look cooked. Transfer the skillet into the oven and cook for 15-17 minutes until the center is set. Let cool for 5 minutes, then slice into 6 slices and serve.